Olive Extract Boosts Hormones

Oleuropein is a compound that occurs naturally in olive oil and helps the body to use proteins more economically. In a Japanese study, published in the Journal of Nutritional Biochemistry, rats that had a protein-rich diet retained no less than 46 percent more protein when large amounts of oleuropein were added to their food. In addition, they produced more testosterone and less cortisol.

Oleuropein is found in olives, olive oil and leaves of the olive tree. Supplements containing olive-leaf extracts have been on the market for years, and if you look carefully you'll find cheap extracts containing 25 percent oleuropein.

The structural formula of the substance is shown below on the left. With a bit of chemical tinkering you can remove the glucose group from the oleuropein molecule, leaving you with a pared-down version  chemists call it an aglycon  of oleuropein. The Japanese experimented with the natural version of oleuropein.

Seven years ago the Japanese reported that virgin olive oil boosted the metabolism of rats.

It was the phenol oleuropein that was responsible for this, they discovered later. [J Nutr Sci Vitaminol (Tokyo). 2008 Oct;54(5):363-70.] Oleuropein boosted the secretion of adrenalin and noradrenalin in rats, and made the brown fat cells burn more fatty acids.

Oleuropein is a compound that occurs naturally in olive oil and helps the body to use proteins more economically. In a Japanese study, published in the Journal of Nutritional Biochemistry, rats that had a protein-rich diet retained no less than 46 percent more protein when large amounts of oleuropein were added to their food. In addition, they produced more testosterone and less cortisol.
The discovery of the adrenergic effect of oleuropein prompted some manufacturers to add oleuropein to bodybuilding supplements. Cobra Labs' pre-workout product The Curse contains an unknown quantity of oleuropein for example. Combined with caffeine this gives users an 'extreme mental focus', if we are to believe Cobra Labs.

Fifteen years ago the same researchers discovered that garlic had approximately the same effect. And when the Japanese combined garlic supplementation with a protein-rich diet, they observed that the garlic boosted anabolism: lab animals retained more nitrogen, and produced more testosterone and less cortisol. That's why the Japanese were curious whether oleuropein also had a similar anabolic effect.

The researchers gave three groups of rats food containing 10, 25 or 40 percent protein [Casein] for 28 days. Half of the rats in each group were given food containing 1 g oleuropein per kg.

The researchers counted the number of nitrogen molecules in the urine and droppings of the rats, which enabled them to calculate how much nitrogen the rats retained. The more nitrogen you retain, the more proteins your body builds up. Nitrogen is an essential component of proteins.

The figure below shows that the rats retained relatively more nitrogen, the more oleuropein they consumed. In the group that ate food containing the most protein, supplementation with oleuropein boosted the amount of nitrogen retained by 46 percent.

In the rats that ate large amounts of protein, oleuropein tripled the concentration of testosterone in the testes, while the concentration of cortisol in the blood went down by more than half.

The figure above reveals part of the mechanism whereby oleuropein boosts testosterone production. The concentration of LH increased as the researchers introduced increasingly higher concentrations of aglycon made from oleuropein into the rats' circulatory system. This increased secretion of LH may be a consequence of the higher adrenalin and noradrenalin levels caused by the oleuropein, the Japanese think.

The researchers believe that these hormonal effects are the key to explaining the anabolic effect of oleuropein.

"Oleuropein supplementation enhances protein anabolism and suppresses protein catabolism owing to hormonal regulation by the stimulation of steroid hormones via noradrenaline, leading to a higher testicular testosterone level and a lower plasma corticosterone level in rats fed a high-protein diet", the researchers conclude.

Interestingly, the rats that were given oleuropein did not put on weight. As far as the researchers could see  although they did not study the effect on body composition extensively  the rats became slimmer. Their fat deposits did shrink at least.

So doing a quick calculation: a rat eats about 50 g feed per kg bodyweight daily. That means 50 mg oleuropein. Converted to human proportions, that means 8 mg oleuropein per kg bodyweight per day. So if you weigh 80 kg, you'd need 640 mg oleuropein daily. If you can get that quantity out of an olive leaf extract that consists of 25 percent oleuropein, youd need about 2.6 g extract each day.